The theory behind how the five realms were connected was simple yet complicated. All the realms were connected to each other but each one stood separate and independent of the others. In order to fully understand how it worked back while he was studying, Miran used to imagine the five realms as five rooms in one house.
At the bottom was the realm of the Forgotten, a place where only desolate dark plains could be found. The realm was the birthplace of low demons and evil. No Guardian had ever made it to that place and the thought of getting trapped there was the worst nightmare to every single one of them. Rumors had it that no energy could survive in that realm and there was no doorway out once you entered. Only demons could move out of the realm at will.